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dharmabum4732
October 12th, 2008, 09:22 PM
Hello,

I'd really like to install Ubuntu on an external hard drive to try it out; but after various attempts, I can't seem to get it to boot. After doing some research I found that this may be a problem with my BIOS settings, but I'm not really sure. At this point, I'd like to start from scratch and ask for some advice before I try again.

Here is an outline of my hardware:

-Motherboard: Asus P5E3 Premium
-Hard drives: 2x298GB in (soft) raid 0
-USB external hard drive (from which I'd like to boot Ubuntu)

I hope that the above information is sufficient: please let me know if any additional information would be helpful.

Best,
-Max

dharmabum4732
October 13th, 2008, 12:09 AM
I tried again, but still no luck.

I installed ubuntu 8.04 from a live CD onto my external hard drive
-The drive was labeled "sdc"
-To avoid affecting my MBR on my internal drives, I clicked on the advanced button at the end of the setup and installed the boot loader on the sdc1 partition.

When I tried to boot up, I configured my BIOS settings to boot from a usb device. Then I get an error. The error is "error 21: selected disk does not exist."

Any suggestions?
-Max

dharmabum4732
October 13th, 2008, 02:35 AM
Hello,

Sorry if it seems like I'm talking to myself, here; but I wanted to include some potentially useful information.

When I booted from the live CD, I did "sudo fdisk -l" in the terminal (I've seen this done in a variety of similar posts).

Here is the outcome:

ubuntu@ubuntu:~$ sudo fdisk -l

Disk /dev/sda: 320.0 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0xbe58e3c5

Device Boot Start End Blocks Id System
/dev/sda1 * 1 77826 625135616 7 HPFS/NTFS

Disk /dev/sdb: 320.0 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x00000000

Disk /dev/sdb doesn't contain a valid partition table

Disk /dev/sdc: 120.0 GB, 120034123776 bytes
255 heads, 63 sectors/track, 14593 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x28f12a69

Device Boot Start End Blocks Id System
/dev/sdc1 * 1 13995 112414806 83 Linux
/dev/sdc2 13996 14593 4803435 5 Extended
/dev/sdc5 13996 14593 4803403+ 82 Linux swap / Solaris

Then I also looked to see what was in the /boot/grub/menu.list file.

Here it is:

title Ubuntu 8.04.1, kernel 2.6.24-19-generic
root (hd2,0)
kernel /boot/vmlinuz-2.6.24-19-generic root=UUID=fb459d9d-1116-448d-aef3-4bdd422fc5a4 ro quiet splash
initrd /boot/initrd.img-2.6.24-19-generic
quiet

title Ubuntu 8.04.1, kernel 2.6.24-19-generic (recovery mode)
root (hd2,0)
kernel /boot/vmlinuz-2.6.24-19-generic root=UUID=fb459d9d-1116-448d-aef3-4bdd422fc5a4 ro single
initrd /boot/initrd.img-2.6.24-19-generic

title Ubuntu 8.04.1, memtest86+
root (hd2,0)
kernel /boot/memtest86+.bin
quiet

Any thoughts?
-Max

caljohnsmith
October 13th, 2008, 03:09 AM
If you told Grub to install to /dev/sdc1, that's the boot sector of the sdc1 partition; the problem with that is you need a boot loader in the MBR (Master Boot Record) in order to boot the HDD. Therefore, you should have used /dev/sdc to install Grub to the MBR.

But the good news is you don't have to reinstall just to put Grub in the MBR of sdc. Just follow these easy steps:

sudo grub
grub> root (hd2,0)
grub> setup (hd2)
grub> quit
And that should make your sdc drive bootable. The next problem is with your menu.lst, so if you can open that up again (as root user), then change all your Ubuntu entries to use "root (hd0,0)" instead of "root (hd2,0)". Let me know how it goes or if you run into problems. :)

dharmabum4732
October 13th, 2008, 03:40 AM
Hi caljohnsmith,

Thanks for the advice! I will try it now and post the results.

dharmabum4732
October 13th, 2008, 04:07 AM
Hi caljohnsmith,

You've solved the problem. Thank you!

caljohnsmith
October 13th, 2008, 01:38 PM
That's great news it's working, and glad I could help out. Cheers and have fun. :)